It's shown side-by-side with footage of the same journey being made through boring old, above-ground traffic, proving that a single car driving at top speed through a dedicated tunnel with no obstacles will get there faster.
"So you turned a four-minute commute into a 90-second commute and all you had to do was spend millions digging a tunnel directly from your house to your destination? Genius! Truly this is a wondrous breakthrough," one Twitter user wrote.
Another said, "Imagine this. Build tunnels and have a passengers ride together so one vehicle is not restricted to one person. Build stations along the way for stops. It's a wild idea I know."
Asked why the original idea had been abandoned, Musk replied: "This is simple and just works." Another user suggested tunnels were "great things to run trains through, not cars".
"Opposite is true," Musk wrote back. "You can have 100s of layers of tunnels, but only one layer on surface (to first approximation), therefore trains should be on surface, cars below."
Even the Twitter account of San Francisco's Bay Area Rapid Transit decided to jump in. "We carry 28,000 people per hour through our Transbay Tube under the bay because of the capacity of a train," it said.
"That's nearly twice as much as cars over the bay. Why wouldn't you prioritise something that carries far more (and safely with automatic train control) over cars?"
Aaron Gordon, a reporter with automotive website Jalopnik, went so far as to label the project a "scam". "I cannot overstate what a scam this whole deal has been," he wrote.
"To recap: Musk's company spent two years developing a very narrow car tunnel. To anyone who ever believed Elon Musk's bullshit: you've been had."
Or as one ZeroHedge reader put it, "There's a Tesla owner born every minute."
- This article originally appeared on News.com.au and has been republished with permission.
